Gitlab Runner occasionally times out at docker build

Summary

Gitlab Runner occasionally times out. After rerunning it mostly works.

Getting source from Git repository
$ eval "$CI_PRE_CLONE_SCRIPT"
Fetching changes...
Initialized empty Git repository in /builds/stadtlandnetz/via_main_docker/.git/
Created fresh repository.
ERROR: Job failed: execution took longer than 1h0m0s seconds

Steps to reproduce

Cannot really reproduce, it happens sometimes, but in the last time more often than ever before (nearly every second pipeline fails).

.gitlab-ci.yml

build-master:
  stage: build
  before_script:
    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
    - docker build -f Dockerfile.xojolinux -t xojo-linux .
  script:
    - docker build -f Dockerfile.via -t registry.gitlab.com/stadtlandnetz/via_main_docker/via-master:$CI_PIPELINE_IID .
    - docker build -f Dockerfile.via -t registry.gitlab.com/stadtlandnetz/via_main_docker/via-master:latest .
    - docker push registry.gitlab.com/stadtlandnetz/via_main_docker/via-master:$CI_PIPELINE_IID
    - docker push registry.gitlab.com/stadtlandnetz/via_main_docker/via-master:latest
  only:
    - master

Actual behavior

Pipeline job starts
reparing the "docker+machine" executor works
Created fresh repository. is the last displayed line,
then it got stuck for 59:00 min.
then the pipleline is reported as failed.

Expected behavior

run through without problems, like before and sometimes

Relevant logs and/or screenshots

see above

Environment description

for this action we use shared Runners (last failed pipeline was on shared-runners-manager-3.gitlab.com (#44028))
we also have one custom Runner installed but it is not used for this pipeline
it doesn't depend on which Runner is used - we saw the pipeline failing and succeeding on all Runners